Occupancy levels in a building, whether an office building, a residence, a place of commerce, or other buildings, may vary over time. Various systems of a building may be adjusted in response to changes in occupancy levels. For example, lighting systems may be turned down or off when a building or a portion thereof is unoccupied.
Throughout the drawings, identical reference numbers may designate similar, but not necessarily identical, elements. Additionally, an index number “N” appended to some of the reference numerals may be understood to merely denote plurality and may not necessarily represent the same quantity for each reference numeral.